Table 2.

Effect of fluoroquinolone resistance selection on the growth of C. perfringens strains (shown by OD₇₅₀) with different concentrations of sodium chloride, urea, sodium lactate, and sodium nitrite^a.

C. perfringens strain	Compound	Wild type	Norfloxacin-resistant	Ciprofloxacin-resistant	Gatifloxacin-resistant
VPI	Sodium chloride	1%	1%	4%∗b	2%
NCTR		2%	2%	2%	1%
3626		2%	2%	2%	2%
13124		6.5%	4%*	6%	2%*
VPI	Urea	6%	6%	4%	4%*
NCTR		6%	4%	3%	2%*
3626		3%	4%	4%	2%
13124		7%	6%	7%∗∗c	6%*
VPI	Sodium lactate	1%	1%	2%*	2%
NCTR		2%	1%	2%**	2%
3626		1%	2%	2%	2%
13124		6%	4%*	5%*	3%**
VPI	Sodium nitrite	60 mM	40 mM*	40 mM*	60 mM
NCTR		60 mM	40 mM	60 mM**	20 mM*
3626		20 mM	40 mM	40 mM	20 mM
13124		60 mM	60 mM	60 mM	40 mM*

^aThe percent (%) or mM value indicates the concentration in which the strain would grow. ^b∗Statistically significant differences are marked by asterisks (P < 0.05). ^c∗∗Better growth was observed for the mutant than for the wild type (P < 0.05) at the concentrations marked by double asterisks.